PHP empty() function : The php empty() function is used to check if variable is empty or not. The empty() function returns true or false.
{echo " True Variable is empty, ";} else {echo " False "; } $my_var=0.0; if(empty($my_var)){echo " True Variable is empty, ";} else {echo " False "; } $my_var=Null; if(empty($my_var)){echo " True Variable is empty, ";} else {echo " False "; } $my_var=False...
PHP - Checking an Empty Array To check whetheran array is empty or not, we can use a built-in functionempty(), in other cases where we want to check if a given variable is empty or not, it can also be used. It returns a Boolean response based on the condition that if the given...
if( isset($_GET['user']) ){ echo ' welcome to the website ' . $_GET['user']; } ?> 1. 2. 3. 4. 5. 6. 测试: http://localhost/isset.php?user=zxl add.php <?php if( isset($_GET['num1']) and isset($_GET['num2']) ){ $num1 = $_GET['num1']; $num...
echo empty($test),empty(100),empty($b=100); Parse error: parse error, unexpected T_LNUMBER, expecting T_STRING or T_VARIABLE or '$' in PHPDocument3 on line 3 is_null函数参数: <?php $test=100; echo is_null($test),is_null...
示例#3 多维数组上使用 empty() <?php$multidimensional = ['some' => ['deep' => ['nested' => 'value'] ]];if (!empty($multidimensional['some']['some']['nested'])) {$someVariable = $multidimensional['some']['deep']['nested'];}var_dump(empty($multidimensional['some-undefined-key'...
To check if a particular variable does exist or, we are going to use PHP isset(). It will return TRUE if the variable exists and return FALSE if it does not exist. Below is the syntax: isset(VARIABLE_NAME) Now let’s see the example below: ...
Theis_string()PHP function is used to check if a type of variable is a string. A string is a data type, such as floating point or integer, but it represents text rather than numbers. A string uses a set of characters that includes spaces and numbers. For instance, an address such as...
'/../autoload.php'; } if (is_file(__DIR__ . '/../vendor/autoload.php')) { require_once __DIR__ . '/../vendor/autoload.php'; } use OSS\Credentials\EnvironmentVariableCredentialsProvider; use OSS\OssClient; use OSS\CoreOssException; // 从环境变量中获取访问凭证。运行本代码示例之前,...
//check_admin()用于检查当前用户权限,如果是admin设置$is_admin变量为true,然后下面判断此变量是否为true,然后执行管理的一些操作。 //ex1.php if(check_admin()) { $is_admin=true; } if($is_admin) { do_something(); } ?> 这一段代码没有将$is_admin事先初始化为Flase,如果register_globals为On,...